Brno, a city of 400,000 people in the south-east of the Czech Republic, may be the place where the European Union's future will be decided. It is also where the country's constitutional court had a session on Tuesday to assess a complaint filed against the Lisbon treaty by a group of rightwing senators associated with the country's Eurosceptic president, Václav Klaus, a staunch opponent of the agreement. As widely expected, the court's hearing was eventually postponed until November 3, so the suspense will only grow.

Already approved by both chambers of the country's parliament, the treaty still needs to be ratified by the Czech president. The problem is that Klaus's renowned aversion to the agreement prompts him to hinder Lisbon's evaluation with anything he can reach.

The president did not show up at the court's session on Tuesday, but sent two representatives to proxy for him. Standing before the jury, they accounted for their principal's objections to the Lisbon treaty by presenting the questions that Klaus had posed to the constitutional court last year, when the judges affirmed the legality of selected parts of the agreement.

The questions embody a small sample of what keeps the Czech president awake at night in his Prague castle residence. First of all, Klaus wanted to know whether, if the treaty is put into practice, his country will remain a sovereign country. Subsequently, there were the president's routine doubts about the EU's charter of fundamental rights, which, as he fears, is not an international treaty, but a new transnational superstate's constitution.

As well as playing on the "national sovereignty at peril" piano, Klaus has been performing a slightly different tune, and stirring up a past that continues to disturb Czechs. The question of the Sudeten Germans, expelled from Czechoslovakia after the second world war, remains a burning question for Czechs. According to Klaus and his fellow Eurosceptics, if Prague accepted the EU's charter of fundamental rights, it would mean the country was exposed to lawsuits from the expellees' descendants. Now, is that something that Czechs should be really worried about?

The anti-EU camp in neighbouring countries, such as Poland and Hungary, has been rallying around the same issue for years, threatening that the Germans would reinstate themselves on their ancestors' lands after the EU's enlargement in 2004. No such thing has happened. Still, Klaus plays the German question like a real virtuoso, justifying his Euroscepticism with the spurious menace, and convincing a significant portion of Czechs that their national interest is indeed in danger.

Should the Czech Republic be granted an opt-out from the charter – which is highly probable, just like the UK and Poland – Klaus has said he would ratify the treaty. Nevertheless, it may be a little premature to open the champagne in Brussels, as the Czech president has found a new ally in neighbouring Slovakia, whose prime minister Robert Fico wants to follow in Klaus's steps and obtain exemptions from the charter of fundamental rights as well.

If this is followed by other member states' demands, the whole negotiating process, hosted by the Swedish presidency, could start all over again. That has been Klaus's objective since the very beginning.